To downgrade to Firefox 3.6 first uninstall Firefox 4 (https://support.mozilla.com/kb/Uninstalling+Firefox), but do not select the option to "Remove my Firefox personal data". If you select that option it will delete your bookmarks, passwords and other user data.

You can then install the latest version of Firefox 3.6 available from http://www.mozilla.com/en-US/firefox/all-older.html - it will automatically use your current bookmarks, passwords etc.

To avoid possible problems with downgrading, I recommend going to your profile folder and deleting the following files if they exist - extensions.cache, extensions.rdf, extensions.ini, extensions.sqlite and localstore.rdf. Deleting these files will force Firefox to rebuild the list of installed extensions, checking their compatibility, and reset toolbar customizations.

For details of how to find your profile folder see https://support.mozilla.com/kb/Profiles

I uninstalled FX 4 and in the process destroyed out all my info. I sat here and looked at my PC for 30 minutes in shock! If you guys made it easier to explain the process I wouldn't have lost everything! Now I am using Enternet explorer..............bummer

YEA!!!!!! I reinstalled Firefox 3.6 and all my information was there!!!!!!!! thank you! and have a great day!!!